Measuring the foliar nutrient levels allows fruit growers to evaluate results from past fertilization and gives the most reliable data on which to base recommendations for future fertility management programs. It's just about time for both berry and tree commercial fruit growers to collect leaf samples for foliar (leaf) nutrient analysis.               

The Extension team is working hard to reopen the soils lab. In the mentime, we recommend growers still take tissue samples at the recommended time for the specific crop (typically between July 15 and 30), and hold it until the soil processing lab reopens. Clean, dried leaves should be held in a dry area in an open paper bag until we are accepting samples. It is best to hold the sample at your farm until we reopen, which we expect to be soon. Please do NOT mail in the sample until our reopening is official.                                                

When you sample, we recommend that you mark the sampled trees with latex paint, so you collect leaves from the same trees each year.  Ideally for tree fruits, collect leaf samples during late July through the first part of August; blueberries the first week of harvesting; strawberries after renovation; and raspberry/blackberry in early to mid August.

Check the plant tissue test information sheet for all details on collecting, handling, and completing information sheets for the samples.  The form contains information on how many leaves need to be collected, where to collect them from on the plant, and other important details.   The tissue test checks levels of nitrogen, phosphorus, potassium, calcium, magnesium, manganese, iron, copper, boron and zinc. Make sure to read and follow the instructions on the Commercial Plant Tissue Test Form

If you have any questions on leaf sampling or if you need additional enrollment information sheets, please contact George Hamilton at the Hillsborough County office or Shyloh Favreau on campus in Durham, NH. 

These blueberry leaves are fully expanded, from this year's new growth - just right for tissue sampling. A complete sample requires at least 40 leaves like these, from 10-20 plants.​​


Fruit & Vegetable Production Field Specialist
Extension Field Specialist, Fruit & Vegetable Production
Phone: (603) 255-3556
Office: Cooperative Extension, Taylor Hall, Durham, NH 03824